This invention relates to a system for collecting and disposing of galley waste in a passenger transport aircraft.
Many passenger transport aircraft currently in service have vacuum toilet systems, in which toilet waste is transported to a waste-holding tank by pressure difference between the aircraft cabin and a vacuum sewer.
A passenger aircraft may include a galley area for food and beverage service. Food service in a passenger transport aircraft is usually accomplished using trays, each bearing the utensils and food items for a complete meal, which are loaded into the aircraft at the start of a flight. The trays are themselves accommodated in special purpose trolleys, each of which may contain several tens of trays. At the start of a food service interval, a flight attendant rolls the trolleys along the aisle and dispenses the trays, with their meals, to the passengers. At the end of the food service interval, the flight attendant retrieves the trays, with unconsumed food items, from the passengers, puts the trays back in the trolley, and rolls the trolley back to the galley area. The flight attendant disposes of liquid waste through a basin which is located in the galley and has an outlet connected through a gray water interface valve to the aircraft drain mast. The liquid from the basin accumulates upstream of the valve, and when the head of the liquid upstream of the valve reaches a certain threshold level, the interface valve opens and the liquid passes through the interface valve to the drain mast and is dumped out of the aircraft.
Solid food waste should not be disposed of through the galley basin because solid objects in the food waste can interfere with closing of the gray water interface valve, with the result that liquid can continue to flow to the drain mast when the valve is nominally in its closed condition. This flow of liquid, which is typically mainly water, may be at a sufficiently low rate that the liquid freezes in the drain mast. Consequently, the drain mast is blocked and the basin is no longer functional. In this case, there is a possibility of liquid backing up upstream of the blockage in the drain mast, even as far as the galley basin, contaminating the galley and causing a public health hazard.
In the case of an aircraft equipped with a vacuum toilet system, the flight attendant may dispose of solid food waste by flushing down one of the toilet bowls of the vacuum toilet system, so that the waste is collected in the holding tank. This is not an optimum solution to the problem of disposal of solid food waste because it interferes with use of the toilet compartment by the passengers. Also, there is a possibility of contamination of the galley by waste containers that have been taken into the toilet compartment.
It is an object of the invention to provide a galley waste disposal system by which solid food waste can be disposed of in a sanitary and convenient manner.